Method And Apparatus For Mixing And Pre-burning Gasification Agent

ABSTRACT

A method and an apparatus for mixing and pre-burning a gasification agent are disclosed. The apparatus includes a gasifier body comprising a furnace chamber, a gas distribution plate, and a gasification agent mixing chamber. The apparatus also includes a pulverized coal transport pipe and a carbon-containing fly ash transport pipe, which respectively feed a pulverized coal and a carbon-containing fly ash to a middle portion of the gasification agent mixing chamber. The apparatus further includes a gasification agent transport pipe that feeds a gasification agent to a bottom of the gasification agent mixing chamber. The present disclosure advocates a pre-burning process of the gasification agent that involves the pulverized coal and the carbon-containing fly ash, which heats the gasification agent as the gasification agent is being fed to the circulating fluidized bed gasifier, thereby ensuring a more complete burning, pyrolysis and gasification of coal within the circulating fluidized bed gasifier.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national stage application of International Application No. PCT/CN2017/088046, filed on Jun. 13, 2017, which claims the priority benefit of China Patent Application No. 201710090522.9, filed on Feb. 20, 2017. The above-identified patent applications are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to the field of coal gasification technologies, and particularly to a method and a device for mixing and pre-burning a gasification agent, which can increase the temperature of the gasification agent entering a circulating fluidized bed gasifier.

BACKGROUND

In order to obtain clean and high temperature fuel gas, various types of gasification apparatuses for converting coal to coal gas have been designed. The emergence of each type of apparatuses has enhanced the development of coal-to-gas technologies to a different extent. However, the apparatuses also have their own insurmountable disadvantages. For example, a fixed bed coal gas generator produces tar and other contaminants, although it can fully burn coal. A circulating fluidized bed coal gasification system does not produce contaminants such as tar, but it cannot fully burn coal and cannot be miniaturized. In addition, an additional auxiliary burning device is required to further burn semicoke and carbon-containing fly ash that cannot be fully burnt by the circulating fluidized bed coal gasification system, resulting in a low rate of single-pass coal gasification. A low-pressure entrained flow bed coal gasification system not only requires very fine pulverized coal and pure oxygen, but also has a high cost of operation. To solve the disadvantages of the apparatuses mentioned above, skilled persons focusing on coal gasification apparatus researches have designed a coal gasification apparatus that adopts a combined gasification process using a circulating fluidized bed and a pyrolysis bed. However, to realize design purposes of the apparatus, it is crucial to ensure a temperature during burning, pyrolysis and gasification in the circulating fluidized bed. To ensure the temperature in the circulating fluidized bed, various ways have been used to preheat a gasification agent entering the circulating fluidized bed, but the result does not meet the expectation and requirements.

Therefore, there is a need for a new technical solution to solve the above problems.

SUMMARY

This section is for the purpose of summarizing some aspects of the present disclosure and to briefly introduce some preferred embodiments. Simplifications or omissions in this section as well as in the abstract or the title of this description may be made to avoid obscuring the purpose of this section, the abstract and the title. Such simplifications or omissions are not intended to limit the scope of the present disclosure.

The present disclosure provides a method and an apparatus for mixing and pre-burning a gasification agent. The method and the apparatus can ensure complete burning, pyrolysis and gasification of coal in a circulating fluidized bed gasifier. This is resulted from a pre-burning process of a gasification agent, wherein high temperature carbon-containing fly ash and pulverized coal are added during a mixing process of the gasification agent. The mixture of high temperature coal gas, the carbon-containing fly ash and the gasification agent are subsequently introduced to a furnace chamber of the circulating fluidized bed gasifier via a gas distribution plate.

According to one aspect of the present disclosure, a method for mixing and pre-burning a gasification agent is provided. According to the method, a gasification agent is fed to a bottom of a gasification agent mixing chamber, and the gasification agent is fully mixed in a lower portion of the gasification agent mixing chamber. A pulverized coal and a coal-containing fly ash are fed to a middle portion of the gasification agent mixing chamber. The method then involves pre-burning, pyrolyzing and gasifying the pulverized coal, the coal-containing fly ash and the gasification agent in the gasification agent mixing chamber to generate a high temperature coal gas and a high temperature fly ash. The method further involves introducing the high temperature coal gas, the high temperature fly ash and the gasification agent to a furnace chamber of a circulating fluidized bed gasifier via a gas distribution plate. The method then involves fully burning, pyrolyzing and gasifying the high temperature coal gas, the high temperature fly ash, the gasification agent and a raw coal in the furnace chamber.

In some embodiments, the gasification agent fed to the bottom of the gasification agent mixing chamber may include high temperature air and water vapor.

In a further embodiment, the gasification agent fed to the bottom of the gasification agent mixing chamber may also include oxygen.

According to another aspect of the present disclosure, an apparatus for mixing and pre-burning a gasification agent is provided. The apparatus comprises a gasifier body, a pulverized coal transport pipe, a carbon-containing fly ash transport pipe, as well as a gasification agent transport pipe. Specifically, the gasifier body may include a furnace chamber provided in an upper portion thereof, a gas distribution plate provided in a middle portion thereof, and a gasification agent mixing chamber provided in a lower portion thereof. The pulverized coal transport pipe is in communication with a middle portion of the gasification agent mixing chamber, and is configured to feed a pulverized coal to the middle portion of the gasification agent mixing chamber. The carbon-containing fly ash transport pipe is also in communication with the middle portion of the gasification agent mixing chamber, and is configured to feed a carbon-containing fly ash to the middle portion of the gasification agent mixing chamber. The gasification agent transport pipe is in communication with a bottom of the gasification agent mixing chamber, and is configured to feed a gasification agent to the bottom of the gasification agent mixing chamber.

In some embodiments, the gasification agent fed to the bottom of the gasification agent mixing chamber may include high temperature air and water vapor.

In some embodiments, the gasification agent transport pipe may include a high temperature air transport pipe and a water vapor transport pipe.

In some embodiments, the gasification agent fed to the bottom of the gasification agent mixing chamber may include high temperature air, water vapor, and oxygen.

In some embodiments, the gasification agent transport pipe may include a high temperature air transport pipe, an oxygen transport pipe, as well as a water vapor transport pipe.

In some embodiments, the apparatus may further include a coal transport pipe and a gas-material mixture transport pipe. Specifically, the coal transport pipe is in communication with the furnace chamber at a middle location of the gasifier body, and is configured to feed a raw coal to the furnace chamber. On the other hand, the gas-material mixture transport pipe is in communication with the furnace chamber at an upper location of the gasifier body.

In comparison with existing techniques, the present disclosure advocates a pre-burning process to heat the gasification agent as the gasification agent is being fed to the circulating fluidized bed gasifier. On the one hand, the pre-burning process would increase the temperature of the gasification agent. On the other hand, the pre-burning process would generate a high temperature coal gas and a carbon-containing fly ash, both of which are introduced into the circulating fluidized bed gasifier, via the gas distribution plate, by the gasification agent which flows at a high speed. This would ensure that the temperature within the circulating fluidized bed gasifier is sufficiently high for burning, pyrolysis and gasification. The present disclosure would result in the gasification agent being at a high temperature, which can be widely used to solve the problem of raising the temperature of gasification agents for various circulating fluidized beds having different gas yields. The present disclosure also provides a solution to fully burning the carbon-containing fly ash.

BRIEF DESCRIPTION OF THE DRAWINGS

To illustrate the technical solutions of embodiments of the present disclosure more clearly, a brief introduction to the accompanying drawings required to describe the embodiments is given below. Obviously, the accompanying drawings in the description below are merely some embodiments of the present disclosure, based on which other drawings may also be obtained by a person of ordinary skill in the art without any inventive efforts. In the drawings:

FIG. 1 is a schematic structural diagram of an apparatus for mixing and pre-burning a gasification agent according to one embodiment of the present disclosure.

In FIG. 1: 1 denotes a gasifier body; 2 denotes a furnace chamber; 3 denotes a coal transport pipe; 4 denotes a gas-material mixture transport pipe; 5 denotes a gas distribution plate; 6 denotes a gas pipe cap; 7 denotes a gasification agent mixing chamber; 8 denotes a pulverized coal transport pipe; 9 denotes a carbon-containing fly ash transport pipe; 10 denotes a gasification agent transport pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed description of the present disclosure is presented largely in terms of procedures, steps, logic blocks, processing, or other symbolic representations that directly or indirectly resemble the operations of devices or systems contemplated in the present disclosure. These descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.

Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be comprised in at least one embodiment of the present disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams or the use of sequence numbers representing one or more embodiments of the present disclosure do not inherently indicate any particular order nor imply any limitations in the present disclosure.

To make the above object, features and advantages of the present disclosure clearer and easier to understand, the present disclosure will be further described in detail below in connection with the accompanying drawings and particular implementations.

“One embodiment” or “embodiment” herein means a specific feature, structure or characteristic that may be included in at least one implementation of the present disclosure. “In one embodiment” throughout the specification refers to neither the same embodiment, nor a separate or optional embodiment contradictory to other embodiments. Unless especially stated, terms indicating a connection such as connected, linked and joined all refer to a direct or indirect connection.

As shown in FIG. 1, an apparatus for mixing and pre-burning a gasification agent according to the present disclosure includes a gasifier body 1, a pulverized coal transport pipe 8, a carbon-containing fly ash transport pipe 9, a gasification agent transport pipe 10, a coal transport pipe 3 and a gas-material mixture transport pipe 4.

The gasifier body 1 includes a furnace chamber 2 provided in an upper portion of the gasifier body 1, a gas distribution plate 5 provided in a middle portion of the gasifier body 1, as well as a gasification agent mixing chamber 7 provided in a lower portion of the gasifier body 1. Both the pulverized coal transport pipe 8 and the carbon-containing fly ash transport pipe 9 are in communication with a middle portion of the gasification agent mixing chamber 7. The gasification agent transport pipe 10 is in communication with a bottom of the gasification agent mixing chamber 7. The pulverized coal transport pipe 8 feeds a pulverized coal to the middle portion of the gasification agent mixing chamber 7. The carbon-containing fly ash transport pipe 9 feeds a carbon-containing fly ash to the middle portion of the gasification agent mixing chamber 7. The gasification agent transport pipe 10 feeds a gasification agent to the bottom of the gasification agent mixing chamber 7. The coal transport pipe 3 is in communication with the furnace chamber 2 at a middle location of the gasifier body 1. The coal transport pipe 3 feeds a raw coal to the furnace chamber 2. The gas-material mixture transport pipe 4 is in communication with the furnace chamber 2 at an upper location of the gasifier body 1. The gas-material mixture transport pipe 4 outputs a gas-material mixture from the furnace chamber 2.

In one embodiment, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 via the gasification agent transport pipe 10 includes high temperature air as well as water vapor. Correspondingly, the gasification agent transport pipe 10 includes a high temperature air transport pipe and a water vapor transport pipe, which are used to respectively feed the high temperature air and the water vapor to the gasification agent mixing chamber 7. The high temperature air and the water vapor are fully mixed in a lower portion of the gasification agent mixing chamber 7. Alternatively, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 may be a gas mixture of high temperature air and water vapor.

In another embodiment, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 via the gasification agent transport pipe 10 includes high temperature air, water vapor, and oxygen. Correspondingly, the gasification agent transport pipe 10 includes a high temperature air transport pipe, a water vapor transport pipe, as well as an oxygen transport pipe, which are used to respectively transport the high temperature air, the water vapor, and the oxygen to the gasification agent mixing chamber 7. The high temperature air, the water vapor, and the oxygen are fully mixed in a lower portion of the gasification agent mixing chamber 7. Alternatively, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 may be a gas mixture of high temperature air, water vapor, and oxygen.

A method for mixing and pre-burning a gasification agent according to the present disclosure is described below with reference to the apparatus for mixing and pre-burning the gasification agent as shown in FIG. 1.

The method for mixing and pre-burning a gasification agent according to the present disclosure includes the following steps: (1) feeding a gasification agent to the bottom of the gasification agent mixing chamber 7, and fully mixing the gasification agent in the lower portion of the gasification agent mixing chamber; (2) feeding a pulverized coal and a coal-containing fly ash to the middle portion of the gasification agent mixing chamber 7; (3) pre-burning, pyrolyzing and gasifying the pulverized coal, the coal-containing fly ash, and the gasification agent in an upper portion of the gasification agent mixing chamber 7 to generate a high temperature coal gas and a high temperature fly ash; (4) introducing the high temperature coal gas, the high temperature fly ash, and the gasification agent to the furnace chamber 2, which may be part of a circulating fluidized bed gasifier, via the gas distribution plate 5; and (5) burning, pyrolyzing and gasifying fully the high temperature coal gas, the high temperature fly ash, the gasification agent, and the raw coal in the furnace chamber 2. In one embodiment, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 is a gas mixture of high temperature air and water vapor. In another embodiment, the gasification agent fed to the bottom of the gasification agent mixing chamber 7 is a gas mixture of high temperature air, oxygen, and water vapor.

In summary, in comparison with existing techniques, the present disclosure advocates a pre-burning process to heat the gasification agent as the gasification agent is being fed to the circulating fluidized bed gasifier. On the one hand, the pre-burning process would increase the temperature of the gasification agent. On the other hand, the pre-burning process would generate a high temperature coal gas and a carbon-containing fly ash, both of which are introduced into the circulating fluidized bed gasifier, via the gas distribution plate, by the gasification agent which flows at a high speed. This would ensure that the temperature within the circulating fluidized bed gasifier is sufficiently high for burning, pyrolysis and gasification. The present disclosure would result in the gasification agent being at a high temperature, which can be widely used to solve the problem of raising the temperature of gasification agents for various circulating fluidized beds having different gas yields. The present disclosure also provides a solution to fully burning the carbon-containing fly ash.

In the present disclosure, unless stated otherwise, terms indicating a connection such as “connected”, “joined”, “linked”, and “coupled” indicate a direct or indirect connection.

It should be noted that any modification made by a person skilled in the art to a specific implementation of the present disclosure does not depart from the scope of the claims of the present disclosure. Accordingly, the scope of the claims of the present disclosure is not merely limited to the specific implementations mentioned above.

Additional Notes

The herein-described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

Further, with respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

Moreover, it will be understood by those skilled in the art that, in general, terms used herein, and especially in the appended claims, e.g., bodies of the appended claims, are generally intended as “open” terms, e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to implementations containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an,” e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more;” the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations. Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

From the foregoing, it will be appreciated that various implementations of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various implementations disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims. 

1. A method, comprising: feeding a gasification agent to a bottom of a gasification agent mixing chamber, wherein the gasification agent is mixed in a lower portion of the gasification agent mixing chamber; feeding a pulverized coal and a coal-containing fly ash to a middle portion of the gasification agent mixing chamber; pre-burning, pyrolyzing and gasifying the pulverized coal, the coal-containing fly ash and the gasification agent in the gasification agent mixing chamber to generate a high temperature coal gas and a high temperature fly ash; introducing the high temperature coal gas, the high temperature fly ash and the gasification agent to a furnace chamber of a circulating fluidized bed gasifier via a gas distribution plate; and burning, pyrolyzing and gasifying the high temperature coal gas, the high temperature fly ash, the gasification agent and a raw coal in the furnace chamber.
 2. The method of claim 1, wherein the gasification agent comprises high temperature air and water vapor.
 3. The method of claim 2, wherein the gasification agent further comprises oxygen.
 4. An apparatus for mixing and pre-burning a gasification agent, comprising: a gasifier body; a pulverized coal transport pipe; a carbon-containing fly ash transport pipe; and a gasification agent transport pipe, wherein: the gasifier body comprises a furnace chamber provided in an upper portion of the gasifier body, a gas distribution plate provided in a middle portion of the gasifier body, and a gasification agent mixing chamber provided in a lower portion of the gasifier body, the pulverized coal transport pipe is in communication with a middle portion of the gasification agent mixing chamber and configured to feed a pulverized coal to the middle portion of the gasification agent mixing chamber, the carbon-containing fly ash transport pipe is in communication with the middle portion of the gasification agent mixing chamber and configured to feed a carbon-containing fly ash to the middle portion of the gasification agent mixing chamber, and the gasification agent transport pipe is in communication with a bottom of the gasification agent mixing chamber and configured to feed a gasification agent to the bottom of the gasification agent mixing chamber.
 5. The apparatus of claim 4, wherein the gasification agent fed to the bottom of the gasification agent mixing chamber comprises high temperature air and water vapor.
 6. The apparatus of claim 5, wherein the gasification agent transport pipe comprises a high temperature air transport pipe and a water vapor transport pipe.
 7. The apparatus of claim 5, wherein the gasification agent fed to the bottom of the gasification agent mixing chamber further comprises oxygen.
 8. The apparatus of claim 7, wherein the gasification agent transport pipe comprises a high temperature air transport pipe, an oxygen transport pipe and a water vapor transport pipe.
 9. The apparatus of claim 4, further comprising: a coal transport pipe; and a gas-material mixture transport pipe, wherein: the coal transport pipe is in communication with the furnace chamber at a middle location of the gasifier body, the coal transport pipe configured to feed a raw coal to the furnace chamber, and the gas-material mixture transport pipe is in communication with the furnace chamber at an upper location of the gasifier body. 